Natural hormones do exist. Our bodies make those all the time. The problem is that sometimes our bodies produce the wrong ones.

What I think you are asking is, "Are herbal hormones effective?"
While some people here on Susan's Place have used herbal hormones with some degree of success, most of us agree that herbals hormones are very mild at best. Some of us go so far as to say that herbals are really a waste of money, because the prescription hormones, which are bio-identical, are many times more effective and they do not cost that much more than herbals hormones. And when you add in the payments from health insurance, they may actually be less expensive.
Prescription hormones are so powerful that your blood levels must be monitored by a doctor familiar with hormone replacement therapy, but the results are truly amazing. Just take a look at the before and after thread here on Susan's Place.
If you want to take herbal hormones, they most likely will do no harm. You may feel a little bit better psychologically because you are now doing something to get you where you need to be with your gender needs. However, do not expect dramatic results.